Large scale extraction of pyrrolizidine alkaloids from tansy ragwort (Senecio jacobaea).

A new technique of large-scale pyrrolizidine alkaloid (PA) extraction was developed in response to toxicity studies on food animals. Results of toxicity experiments on cattle vary from those on rodents (2); therefore, dose/response studies need to be germaine to the appropriate species. This new technique for extraction utilizes protonation of the ring nitrogen and partition of solvent to preferentially extract the alkaloid.

Thin-layer agarose isoelectric focusing: an improved technique for determining sheep hemoglobin type.

An improved technique for rapid screening of sheep flocks for hemoglobin (Hb) type is presented. This technique, isoelectric focusing (IEF) on thin-layer agarose gels is simple, rapid, inexpensive and is suitable for screening large numbers of sheep for Hb type. With this technique, up to 100 sheep blood samples can be prepared, tested and interpreted within 2 h after samples are drawn.

Immunotoxicity of technical pentachlorophenol (PCP-T): depressed humoral immune responses to T-dependent and T-independent antigen stimulation in PCP-T exposed mice.

The effects of chronic dietary exposure to technical pentachlorophenol (PCP-T) on humoral immune responses in mice were examined. Primary and secondary splenic antibody responses to the T-dependent antigen, sheep red blood cells (SRBC), were examined in Swiss-Webster mice using our recently developed screening technique, the Hemolytic Antibody Isotope Release (HAIR) assay. To assess direct effects of PCP-T on B cells, the splenic plaque-forming cell response and serum antibody titers to the T-independent antigen, dinitrophenyl (DNP)-Ficoll, were examined.

Effect of Feeding Lactobacilli on the Coliform and Lactobacillus Flora of Intestinal Tissue and Feces from Piglets .

Development of fecal Lactobacillus and coliform in healthy newborn pigs during the first 48 h after birth was studied. Lactobacilli were detected (10 per g) in the feces of newborn pigs as early as 4 h after birth and colifroms by 8 h (10 per g). By 24 h the two types were present in near equal numbers (10 to 10/g).